When they first tackled their respective roles of Charles Xavier and Magneto in 2000’s X-Men, there’s no way Patrick Stewart and Ian McKellen could have dreamed they’d still be talking about the parts nearly 14 years later … and possibly for years to come. But the respected thespians continue to delve into all things mutant as Fox educates audiences on next summer’s X-Men: Days of Future Past, which original X-Men helmer Bryan Singer will return to direct.

For example, did you know that for the first time on screen, McKellen and Stewart will "act" alongside much younger versions of their characters, played by the First Class stars James McAvoy and Michael Fassbender? When asked if the veteran actors synched their performances to match McAvoy and Fassy, McKellen joked to the Wall Street Journal, "No, it’s up to them to sync with us."

All sides will have to synch if Singer is going to pull his sprawling story off. Days of Future Past tells a tale that spans decades, with the antihero Wolverine (Hugh Jackman) traveling from the future to the past to try and help the X-Men prevent an event that alters our timeline and creates a post-apocalyptic reality in the distant setting. It is based on a very popular storyline from the X-Men comics, but will make a few key changes on the way to the screen.

The use of the word "apocalyptic" takes on a cryptic meaning now that Fox and Singer already have announced that Future Past will be followed by X-Men: Apocalypse in 2016. Again, this is a story that should involve a classic X-Men villain… though Stewart and McKellen swear that they know nothing at all about the sequel or their potential roles in it. Stewart tell the WSJ:

"I don’t know if Ian knows anything about this. I know nothing about this. Another X-Men movie has been announced. … Has anyone called you? Are you keeping something from me?"

To which McKellen responded:

"No, I know nothing about it. Which probably means we’re not in it."

There have been precious few X-Men movies without these two gems since the franchise launched. Though what we are hearing about Apocalypse is that it will be a traditional sequel to First Class, with a heavy emphasis on McAvoy and Fassbender. So maybe Stewart and McKellen – who are no strangers to sequels and multi-part franchises – will get a short rest? Listen to them tell the story below. Are they playing coy? Do they really have no part in Apocalypse? Or is it just too soon to tell?